Driving is a highly visual task but accident statistics show that driver inattention is a contributory factor in the majority of accidents. Recent data from the United States Department of Transport indicates that in certain circumstances, doing menial tasks, like carrying on a conversation with a passenger, helps to maintain the drivers attention and hence reduce the probability of an accident. Various schemes have been proposed for monitoring the alertness of a driver of a vehicle.
For example, U.S. Pat. No. 5,012,226 describes a system which provides a visual activation of some device at set intervals and then waits for the driver to activate a switch to indicate awareness.
U.S. Pat. No. 6,154,123 describes a similar system which uses voice recognition technology to record the driver's verbal acknowledgement that he has noticed a visual prompt.
These known systems provide means for detecting whether a driver is alert or not but cannot necessarily maintain a state of alertness in the driver.